Die for forming tooth-backings.



H. L. GRUTTENDEN. DIE FOR FORMING TOOTH BACKINGS.

APPLICATION FILED APILZI, 1913.

Patented Oct. 28, 1913.

UTTE STATES PATENT OFFICE.

HENRY L. CRU'ITENDEN, OF NORTHFIELD, MINNESOTA.

DIE FOR FORMING- TOUTH-BACKINGS.

To all 107mm 2'6 may concern:

Be it known that T, HENRY L. Currrrnnnew, a citizen of the United States, residing at Northfield, in the county of Rice and State of Minnesota, have invented certain new and useful Improvements in Dies for Forming ll ooth-Backings; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention has for its object to provide an extremely simple and higl'ily ellicient instrument for use in forming dental tooth backings, and to such ends, the invention consists of the novel devices and combinations of devices hereinafter described and defined in the claim. As is well known, a tooth backing of this character is formed from a thin piece of sheet metal, gold, platinum, alloy, or other metal, which is first bent to form a beaded rib, and is then bent to fit the back of the artificial tooth to which it is to be applied. An artificial tooth of this character, of course, has a groove that receives the beaded rib of the backing and interlocks therewith, with sort of a dove-tailed action.

My improved instrument for forming these backings, is in the nature of a twopart die, the die sections having a cooperating supplemental rib forming groove adjacent to flat anvil faces. Also, the die sections are connected by dowel pins located or close to the rib forming grooves thereof, so that they serve also gage pins or stops for limiting the projection of the folded backing forming plate between the die sections.

In the accompanying drawings which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings, Figure 1 is a plan view of the improved die or forming instrument; Fig. 2 is a vertical section taken on the line m ac on Fig. 1; Fig. 3 is a transverse vertical section taken on the line w- -w on Fig. 2; Fig. 1 is a plan view showing a thin sheet-metal blank from which a backing is adapted to be formed; Figs. 5, 6 and 7 are perspective views illustrating different steps in the formation of the backing; and Fig. 8 shows the backing applied to an artificial tooth.

The numeral 1 indicates the two sections of the die or forming instrument. These Specification of Letters Patent.

Application filed Apri121, 1913.

Patented Oct. 28, 1913. Serial No. 762,511.

die blocks or sections, on their upper faces, are formed with smooth and flat anvil for1ning surfaces 2. One of the die blocks, as shown, the right hand member, is provided with rigidly secured parallel laterally projecting dowel pins 3 that closely fit alined seats lin the cooperating die block. Just above the dowel pins 3, and just below their anvil surfaces 2, the die blocks are formed on their opposing or inner faces with supplemental rib forming grooves or channels 53. Both die blocks are preferably rectangular structures having reduced lower end portions 1 adapting them to be applied between and rested on the jaws of the vise.

The numeral (3 indicates a so-called matrix pin which is used in the formation of the backing.

The numeral 7 indicates an artificial tooth of standard construction, having in its back a dove-tailed groove to receive the rib of the backing.

The manner of using the improved former is substantially as follows: Preferably, the reduced lower end portions of the die blocks 1 are placed between the jaws of the vise with the shouldered portions of said block resting on the jaws, so that the die will not slip through and between the jaws of the vise. One of the backing forming plates 6:, Fig. l, which will usually be about thirty or thirty-two gage, is doubled and bent over the matrix pin 6, as shown in Fig. 5. Then the folded portion of this plate a and the matrix pin 6 are placed between the die blocks, alined with the channels thereof, and supported by the dowel pins 3, which, at such, times, serve as gage pins to prevent the said plate a from being moved too far downward between the said die blocks. Then by tightening the jaws of the vise onto the die blocks, the said die blocks are tightly forced together and onto the en gaged portion of the plate a, and by this action, the said plate a is formed with a beaded rib a This so-called beaded rib a will lit in the groove of the tooth 7 and will interlock therewith, with a dove-tailed action. Next, the flanges of the plate may be bent downward and hammered against the anvil surfaces 2 until they have become perfectly flat. This brings the backing plate to the form best shown in Fig. 6. The vise being loosened and the pin 6 removed from the rib a the late a ma be shifted to a pos1t1on shown 1n Fig. 3, the vise agaln tightened and the rib a cut or filed off at one end, as shown in Figs. 8 and 7 Then the projecting end of the plate a may be bent over, as shown in Fig. 3, so that it will fit the beveled end of the tooth 7. The backing plate being then slipped onto the tooth 7 its projecting edge will be filed OH to fit the tooth.

hat I claim is:

An instrument for use in forming dental tooth backings, comprising cooperating relatively movable die-blocks connected by dowel pins and having anvil surfaces and ribforming grooves adjacent to said anvil surfaces, the said dowel pins serving to hold said die blocks in alinement and being extended immediately adjacent to the said ribforming grooves and serving as gage pins, substantially as described.

In testimony whereof I ailix my signature in presence of two Witnesses.

HENRY L. CRUTTENDFN.

Witnesses:

FREDERICK L. LAURENCE, I. F. SEELEY.

Copies of this patent may be obtained for five cents each, by addressing the Washington, D. C.

Commissioner of Patents 

